Flowable Thermoplastics with Halogen Flame Retardancy System

ABSTRACT

Thermoplastic molding compositions, comprising A) from 10 to 98% by weight of at least one thermoplastic polymer, B) from 0.01 to 50% by weight of B1) at least one highly branched or hyperbranched polycarbonate with an OH number of from 1 to 600 mg KOH/g of polycarbonate (to DIN 53240, part 2), or 
     B2) at least one highly branched or hyperbranched polyester of A x B y  type, where x is at least 1.1 and y is at least 2.1, or a mixture of these, C) from 1 to 30% by weight of a flame retardant combination composed of, based on 100% by weight of C), C1) from 20 to 99% by weight of a halogen-containing flame retardant, C2) from 1 to 80% by weight of an antimony oxide, D) from 0 to 60% by weight of other additives, where the total of the percentages by weight of components A) to D) is 100%.

The invention relates to thermoplastic molding compositions comprising

-   A) from 10 to 98% by weight of at least one thermoplastic polymer,-   B) from 0.01 to 50% by weight of-   B1) at least one highly branched or hyperbranched polycarbonate with    an OH number of from 1 to 600 mg KOH/g of polycarbonate (to DIN    53240, part 2), or-   B2) at least one highly branched or hyperbranched polyester of    A_(x)B_(y) type, where x is at least 1.1 and y is at least 2.1,    -   or a mixture of these,-   C) from 1 to 30% by weight of a flame retardant combination composed    of, based on 100% by weight of C),-   C1) from 20 to 99% by weight of a halogen-containing flame    retardant,-   C2) from 1 to 80% by weight of an antimony oxide,-   D) from 0 to 60% by weight of other additives,    where the total of the percentages by weight of components A) to D)    is 100%.

The invention further relates to the use of the inventive moldingcompositions for production of fibers, films, or moldings, and also tothe resultant moldings of any type.

EP-A 410 301 and EP-A 736 571 disclose by way of example polyesters andpolyamides comprising halogen-containing flame retardant, antimonyoxides mostly being used as synergists in these polymers.

To improve flowability, low-molecular-weight additives are usually addedto thermoplastics. However, the action of these additives is subject tosevere restriction, because, for example, the deterioration ofmechanical properties becomes unacceptable on increasing the amountadded of the additive, and also because the effectiveness of the flameretardancy system mostly falls.

WO-97/45474 discloses thermoplastic compositions which comprisedendrimeric polyesters in the form of an AB₂ molecule in a polyester.Here, a polyhydric alcohol as core molecule reacts withdimethylpropionic acid as AB₂ molecule to give a dendrimeric polyester.This contains only OH functionalities at the end of the chain.Disadvantages of these mixtures are the high glass transitiontemperature of the dendrimeric polyesters, the comparatively complicatedpreparation process, and especially the poor solubility of thedendrimers in the polyester matrix.

According to the teaching of DE-A 101 32 928, the incorporation ofbranching agents of this type by means of compounding and solid-phasepost-condensation improves mechanical properties (molecular weightincrease). Disadvantages of the process variant described are the longpreparation time and the disadvantageous properties previouslymentioned.

DE 102004 005652.8 and DE 102004 005657.9 have previously proposed novelflow improvement additives for polyesters.

An object on which the present invention was based was therefore toprovide thermoplastic, flame-retardant polymer molding compositionswhich have good flowability together with good mechanical properties,and also flame-retardant properties. In particular, the additive isintended neither to exude nor to have any tendency toward mold deposit.

The advantageous effect is in principle apparent in the inventivemolding compositions for thermoplastics of any type. By way of example,a list of suitable thermoplastics is found in Kunststoff-Taschenbuch[Plastics handbook] (Ed. Saechtling), 1989 edition, which also givessources of supply. Processes for preparation of these thermoplastics areknown per se to the person skilled in the art.

Preferred thermoplastics are those selected from the group of thepolyamides, vinylaromatic polymers, ASA polymers, ABS polymers, SANpolymers, POM, PPE, polyarylene ether sulfones, preference being givento polyesters and polycarbonates.

The inventive molding compositions comprise, as component (A), from 10to 98% by weight, preferably from 30 to 97.99% by weight, and inparticular from 30 to 95% by weight, of at least one thermoplasticpolymer, preferably polyesters/polycarbonates.

Use is generally made of polyesters A) based on aromatic dicarboxylicacids and on an aliphatic or aromatic dihydroxy compound.

A first group of preferred polyesters is that of polyalkyleneterephthalates, in particular those having from 2 to 10 carbon atoms inthe alcohol moiety.

Polyalkylene terephthalates of this type are known per se and aredescribed in the literature. Their main chain contains an aromatic ringwhich derives from the aromatic dicarboxylic acid. There may also besubstitution in the aromatic ring, e.g. by halogen, such as chlorine orbromine, or by C₁-C₄-alkyl groups, such as methyl, ethyl, iso- orn-propyl, or n-, iso- or tert-butyl groups.

These polyalkylene terephthalates may be prepared by reacting aromaticdicarboxylic acids, or their esters or other ester-forming derivatives,with aliphatic dihydroxy compounds in a manner known per se.

Preferred dicarboxylic acids are 2,6-naphthalenedicarboxylic acid,terephthalic acid and isophthalic acid, and mixtures of these. Up to 30mol %, preferably not more than 10 mol %, of the aromatic dicarboxylicacids may be replaced by aliphatic or cycloaliphatic dicarboxylic acids,such as adipic acid, azelaic acid, sebacic acid, dodecanedioic acids andcyclohexanedicarboxylic acids.

Preferred aliphatic dihydroxy compounds are diols having from 2 to 6carbon atoms, in particular 1,2-ethanediol, 1,3-propanediol,1,4-butanediol, 1,6-hexanediol, 1,4-hexanediol, 1,4-cyclohexanediol,1,4-cyclohexanedimethanol and neopentyl glycol, and mixtures of these.

Particularly preferred polyesters (A) are polyalkylene terephthalatesderived from alkanediols having from 2 to 6 carbon atoms. Among these,particular preference is given to polyethylene terephthalate,polypropylene terephthalate and polybutylene terephthalate, and mixturesof these. Preference is also given to PET and/or PBT which comprise, asother monomer units, up to 1% by weight, preferably up to 0.75% byweight, of 1,6-hexanediol and/or 2-methyl-1,5-pentanediol.

The viscosity number of the polyesters (A) is generally in the rangefrom 50 to 220, preferably from 80 to 160 (measured in 0.5% strength byweight solution in a phenol/o-dichlorobenzene mixture in a weight ratioof 1:1 at 25° C. in accordance with ISO 1628).

Particular preference is given to polyesters whose carboxy end groupcontent is up to 100 mval/kg of polyester, preferably up to 50 mval/kgof polyester and in particular up to 40 mval/kg of polyester. Polyestersof this type may be prepared, for example, by the process of DE-A 44 01055. The carboxy end group content is usually determined by titrationmethods (e.g. potentiometry).

Particularly preferred molding compositions comprise, as component A), amixture of polyesters other than PBT, for example polyethyleneterephthalate (PET). The proportion of the polyethylene terephthalate,for example, in the mixture is preferably up to 50% by weight, inparticular from 10 to 35% by weight, based on 100% by weight of A).

It is also advantageous to use recycled PET materials (also termed scrapPET), if appropriate mixed with polyalkylene terephthalates, such asPBT.

Recycled materials are generally:

-   1) those known as post-industrial recycled materials: these are    production wastes during polycondensation or during processing, e.g.    sprues from injection molding, start-up material from injection    molding or extrusion, or edge trims from extruded sheets or films.-   2) post-consumer recycled materials: these are plastic items which    are collected and treated after utilization by the end consumer.    Blow-molded PET bottles for mineral water, soft drinks and juices    are easily the predominant items in terms of quantity.

Both types of recycled material may be used either as ground material orin the form of pellets. In the latter case, the crude recycled materialsare separated and purified and then melted and pelletized using anextruder. This usually facilitates handling and free flow, and meteringfor further steps in processing.

The recycled materials used may either be pelletized or in the form ofregrind. The edge length should not be more than 10 mm, preferably lessthan 8 mm.

Because polyesters undergo hydrolytic cleavage during processing (due totraces of moisture) it is advisable to predry the recycled material. Theresidual moisture content after drying is preferably <0.2%, inparticular <0.05%.

Another group to be mentioned is that of fully aromatic polyestersderiving from aromatic dicarboxylic acids and aromatic dihydroxycompounds.

Suitable aromatic dicarboxylic acids are the compounds previouslymentioned for the polyalkylene terephthalates. The mixtures preferablyused are composed of from 5 to 100 mol % of isophthalic acid and from 0to 95 mol % of terephthalic acid, in particular from about 50 to about80% of terephthalic acid and from 20 to about 50% of isophthalic acid.

The aromatic dihydroxy compounds preferably have the formula

where Z is an alkylene or cycloalkylene group having up to 8 carbonatoms, an arylene group having up to 12 carbon atoms, a carbonyl group,a sulfonyl group, an oxygen atom, or sulfur atom, or a chemical bond,and m is from 0 to 2. The phenylene groups of the compounds may alsohave substitution by C₁-C₆-alkyl or alkoxy groups and fluorine, chlorineor bromine.

Examples of parent compounds for these compounds are

-   dihydroxybiphenyl,-   di(hydroxyphenyl)alkane,-   di(hydroxyphenyl)cycloalkane,-   di(hydroxyphenyl)sulfide,-   di(hydroxyphenyl)ether,-   di(hydroxyphenyl)ketone,-   di(hydroxyphenyl)sulfoxide,-   α,α′-di(hydroxyphenyl)dialkylbenzene,-   di(hydroxyphenyl)sulfone, di(hydroxybenzoyl)benzene,-   resorcinol, and-   hydroquinone, and also the ring-alkylated and ring-halogenated    derivatives of these.

Among these, preference is given to

-   4,4′-dihydroxybiphenyl,-   2,4-di(4′-hydroxyphenyl)-2-methylbutane,-   α,α′-di(4-hydroxyphenyl)-p-diisopropylbenzene,-   2,2-di(3′-methyl-4′-hydroxyphenyl)propane, and-   2,2-di(3′-chloro-4′-hydroxyphenyl)propane,    and in particular to-   2,2-di(4′-hydroxyphenyl)propane-   2,2-di(3′,5-dichlorodihydroxyphenyl)propane,-   1,1-di(4′-hydroxyphenyl)cyclohexane,-   3,4′-dihydroxybenzophenone,-   4,4′-dihydroxydiphenyl sulfone and-   2,2-di(3′,5′-dimethyl-4′-hydroxyphenyl)propane    and mixtures of these.

It is, of course, also possible to use mixtures of polyalkyleneterephthalates and fully aromatic polyesters. These generally comprisefrom 20 to 98% by weight of the polyalkylene terephthalate and from 2 to80% by weight of the fully aromatic polyester.

It is, of course, also possible to use polyester block copolymers, suchas copolyether-esters. Products of this type are known per se and aredescribed in the literature, e.g. in U.S. Pat. No. 3,651,014.Corresponding products are also available commercially, e.g. Hytrel®(DuPont).

According to the invention, polyesters include halogen-freepolycarbonates. Examples of suitable halogen-free polycarbonates arethose based on diphenols of the general formula

where Q is a single bond, a C₁-C₈-alkylene group, a C₂-C₃-alkylidenegroup, a C₃-C₆-cycloalkylidene group, a C₆-C₁₂-arylene group, or —O—,—S— or —SO₂—, and m is a whole number from 0 to 2.

The phenylene radicals of the diphenols may also have substituents, suchas C₁-C₆-alkyl or C₁-C₆-alkoxy.

Examples of preferred diphenols of the formula are hydroquinone,resorcinol, 4,4′-dihydroxybiphenyl, 2,2-bis(4-hydroxyphenyl)propane,2,4-bis(4-hydroxyphenyl)-2-methylbutane and1,1-bis(4-hydroxyphenyl)cyclohexane. Particular preference is given to2,2-bis(4-hydroxyphenyl)propane and 1,1-bis(4-hydroxyphenyl)cyclohexane,and also to 1,1-bis(4-hydroxyphenyl)-3,3,5-trimethylcyclohexane.

Either homopolycarbonates or copolycarbonates are suitable as componentA, and preference is given to the copolycarbonates of bisphenol A, aswell as to bisphenol A homopolymer.

Suitable polycarbonates may be branched in a known manner, specificallyby incorporating 0.05 to 2.0 mol %, based on the total of the biphenolsused, of at least trifunctional compounds, for example those havingthree or more phenolic OH groups.

Polycarbonates which have proven particularly suitable have relativeviscosities η_(ref) of from 1.10 to 1.50, in particular from 1.25 to1.40. This corresponds to an average molar mass M_(w) (weight-average)of from 10 000 to 200 000 g/mol, preferably from 20 000 to 80 000 g/mol.

The diphenols of the general formula are known per se or can be preparedby known processes.

The polycarbonates may, for example, be prepared by reacting thediphenols with phosgene in the interfacial process, or with phosgene inthe homogeneous-phase process (known as the pyridine process), and ineach case the desired molecular weight may be achieved in a known mannerby using an appropriate amount of known chain terminators. (In relationto polydiorganosiloxane-containing polycarbonates see, for example, DE-A33 34 782.)

Examples of suitable chain terminators are phenol, p-tert-butylphenol,or else long-chain alkylphenols, such as 4-(1,3-tetramethylbutyl)phenolas in DE-A 28 42 005, or monoalkylphenols, or dialkylphenols with atotal of from 8 to 20 carbon atoms in the alkyl substituents as inDE-A-35 06 472, such as p-nonylphenol, 3,5-di-tert-butylphenol,p-tert-octylphenol, p-dodecylphenol, 2-(3,5-dimethylheptyl)phenol and4-(3,5-dimethylheptyl)phenol.

For the purposes of the present invention, halogen-free polycarbonatesare polycarbonates composed of halogen-free biphenols, of halogen-freechain terminators and, if used, of halogen-free branching agents, wherethe content of subordinate amounts at the ppm level of hydrolyzablechlorine, resulting, for example, from the preparation of thepolycarbonates with phosgene in the interfacial process, is not regardedas meriting the term halogen-containing for the purposes of theinvention. Polycarbonates of this type with contents of hydrolyzablechlorine at the ppm level are halogen-free polycarbonates for thepurposes of the present invention.

Other suitable components A) which may be mentioned are amorphouspolyester carbonates, where during the preparation process phosgene hasbeen replaced by aromatic dicarboxylic acid units, such as isophthalicacid and/or terephthalic acid units. Reference may be made at this pointto EP-A 711 810 for further details.

EP-A 365 916 describes other suitable copolycarbonates having cycloalkylradicals as monomer units.

It is also possible for bisphenol A to be replaced by bisphenol TMC.Polycarbonates of this type are obtainable from Bayer with the trademarkAPEC HT®.

As component B), the inventive molding compositions comprise from 0.01to 50% by weight, preferably from 0.5 to 20% by weight, and inparticular from 0.7 to 10% by weight, of a mixture composed of B1) atleast one highly branched or hyperbranched polycarbonate having an OHnumber of from 1 to 600 mg KOH/g of polycarbonate, preferably from 10 to550 mg KOH/g of polycarbonate, and in particular from 50 to 550 mg KOH/gof polycarbonate (to DIN 53240, Part 2), or of at least onehyperbranched polyester as component B2) or a mixture of these, asexplained below.

For the purposes of this invention, hyperbranched polycarbonates B1) arenon-crosslinked macromolecules having hydroxy groups and carbonategroups, these having both structural and molecular non-uniformity. Theirstructure may firstly be based on a central molecule in the same way asdendrimers, but with non-uniform chain length of the branches. Secondly,they may also have a linear structure with functional pendant groups, orelse they may combine the two extremes, having linear and branchedmolecular portions. See also P. J. Flory, J. Am. Chem. Soc. 1952, 74,2718, and H. Frey et al., Chem. Eur. J. 2000, 6, no. 14, 2499 for thedefinition of dendrimeric and hyperbranched polymers.

“Hyperbranched” in the context of the present invention means that thedegree of branching (DB), i.e. the average number of dendritic linkagesplus the average number of end groups per molecule, is from 10 to 99.9%,preferably from 20 to 99%, particularly preferably from 20 to 95%.

“Dendrimeric” in the context of the present invention means that thedegree of branching is from 99.9 to 100%. See H. Frey et al., ActaPolym. 1997, 48, 30 for the definition of “degree of branching”.

Component B1) preferably has a number-average molar mass M, of from 100to 15 000 g/mol, preferably from 200 to 12 000 g/mol, and in particularfrom 500 to 10 000 g/mol (GPC, PMMA standard).

The glass transition temperature Tg is in particular from −80 to +140°C., preferably from −60 to 120° C. (according to DSC, DIN 53765).

In particular, the viscosity (mPas) at 23° C. (to DIN 53019) is from 50to 200 000, in particular from 100 to 150 000, and very particularlypreferably from 200 to 100 000.

Component B1) is preferably obtainable via a process which comprises atleast the following steps:

-   a) reaction of at least one organic carbonate (A) of the general    formula RO[(CO)]_(n)OR with at least one aliphatic,    aliphatic/aromatic, or aromatic alcohol (B) which has at least three    OH groups, with elimination of alcohols ROH to give one or more    condensates (K), where each R, independently of the others, is a    straight-chain or branched aliphatic, aromatic/aliphatic, or    aromatic hydrocarbon radical having from 1 to 20 carbon atoms, and    where the radicals R may also have bonding to one another to form a    ring, and n is a whole number from 1 to 5, or-   ab) reaction of phosgene, diphosgene or triphosgene with the    abovementioned alcohol (B) with elimination of hydrogen chloride.    -   and also-   b) intermolecular reaction of the condensates (K) to give a highly    functional highly branched, or highly functional hyperbranched    polycarbonate,    where the quantitative proportion of the OH groups to the carbonates    in the reaction mixture is selected in such a way that the    condensates (K) have an average of either one carbonate group and    more than one OH group or one OH group and more than one carbonate    group.

The starting material used may comprise phosgene, diphosgene, ortriphosgene, and preference here is given to organic carbonates.

Each of the radicals R of the organic carbonates (A) used as startingmaterial and having the general formula RO(CO)OR is, independently ofthe others, a straight-chain or branched aliphatic, araliphatic, oraromatic hydrocarbon radical having from 1 to 20 carbon atoms. The tworadicals R may also have bonding to one another to form a ring. Theradical is preferably an aliphatic hydrocarbon radical, and particularlypreferably a straight-chain or branched alkyl radical having from 1 to 5carbon atoms, or a substituted or unsubstituted phenyl radical.

In particular, simple carbonates of the formula RO(CO)OR are used; n ispreferably from 1 to 3, in particular 1.

By way of example, dialkyl or diaryl carbonates may be prepared from thereaction of aliphatic, araliphatic, or aromatic alcohols, preferablymonoalcohols, with phosgene. They may also be prepared by way ofoxidative carbonylation of the alcohols or phenols by means of CO in thepresence of noble metals, oxygen, or NO_(x). In relation to preparationmethods for diaryl or dialkyl carbonates, see also “Ullmann'sEncyclopedia of Industrial Chemistry”, 6th edition, 2000 ElectronicRelease, published by Wiley-VCH.

Examples of suitable carbonates comprise aliphatic, aromatic/aliphatic,or aromatic carbonates, such as ethylene carbonate, propylene 1,2- or1,3-carbonate, diphenyl carbonate, ditolyl carbonate, dixylyl carbonate,dinaphthyl carbonate, ethyl phenyl carbonate, dibenzyl carbonate,dimethyl carbonate, diethyl carbonate, dipropyl carbonate, dibutylcarbonate, diisobutyl carbonate, dipentyl carbonate, dihexyl carbonate,dicyclohexyl carbonate, diheptyl carbonate, dioctyl carbonate, didecylcarbonate, or didodecyl carbonate.

Examples of carbonates in which n is greater than 1 comprise dialkyldicarbonates, such as di(tert-butyl) dicarbonate, or dialkyltricarbonates, such as di(tert-butyl) tricarbonate.

Preference is given to use of aliphatic carbonates, in particular thosein which the radicals comprise from 1 to 5 carbon atoms, e.g. dimethylcarbonate, diethyl carbonate, dipropyl carbonate, dibutyl carbonate, ordiisobutyl carbonate.

The organic carbonates are reacted with at least one aliphatic alcohol(B) which has at least 3 OH groups, or with mixtures of two or moredifferent alcohols.

Examples of compounds having at least three OH groups comprise glycerol,trimethylolmethane, trimethylolethane, trimethylolpropane,1,2,4-butanetriol, tris(hydroxymethyl)amine, tris(hydroxyethyl)amine,tris(hydroxypropyl)amine, pentaerythritol, diglycerol, triglycerol,polyglycerols, bis(trimethylolpropane), tris(hydroxymethyl)isocyanurate,tris(hydroxyethyl)isocyanurate, phloroglucinol, trihydroxytoluene,trihydroxydimethylbenzene, phloroglucides, hexahydroxybenzene,1,3,5-benzenetrimethanol, 1,1,1-tris(4′-hydroxyphenyl)methane,1,1,1-tris(4′-hydroxyphenyl)ethane, bis(trimethylolpropane), or sugars,such as glucose, tri- or polyhydric polyetherols based on tri- orpolyhydric alcohols and ethylene oxide, propylene oxide, or butyleneoxide, or polyesterols. Particular preference is given here to glycerol,trimethylolethane, trimethylolpropane, 1,2,4-butanetriol,pentaerythritol, and also their polyetherols based on ethylene oxide orpropylene oxide.

These polyhydric alcohols may also be used in a mixture with dihydricalcohols (B′), with the proviso that the average OH functionality of allof the alcohols used together is greater than 2. Examples of suitablecompounds having two OH groups comprise ethylene glycol, diethyleneglycol, triethylene glycol, 1,2- and 1,3-propanediol, dipropyleneglycol, tripropylene glycol, neopentyl glycol, 1,2-, 1,3-, and1,4-butanediol, 1,2-, 1,3-, and 1,5-pentanediol, hexanediol,cyclopentanediol, cyclohexanediol, cyclohexanedimethanol,bis(4-hydroxycyclohexyl)methane, bis(4-hydroxycyclohexyl)ethane,2,2-bis(4-hydroxycyclohexyl)propane,1,1′-bis(4-hydroxyphenyl)-3,3,5-trimethylcyclohexane, resorcinol,hydroquinone, 4,4′-dihydroxyphenol, bis-(4-bis(hydroxyphenyl)sulfide,bis(4-hydroxyphenyl)sulfone, bis(hydroxymethyl)benzene,bis(hydroxymethyl)toluene, bis(p-hydroxyphenyl)methane,bis(p-hydroxyphenyl)ethane, 2,2-bis(p-hydroxyphenyl)propane,1,1-bis(p-hydroxyphenyl)cyclohexane, dihydroxybenzophenone, dihydricpolyether polyols based on ethylene oxide, propylene oxide, butyleneoxide, or mixtures of these, polytetrahydrofuran, polycaprolactone, orpolyesterols based on diols and dicarboxylic acids.

The diols serve for fine adjustment of the properties of thepolycarbonate. If use is made of dihydric alcohols, the ratio ofdihydric alcohols B′) to the at least trihydric alcohols (B) is set bythe person skilled in the art as a function of the desired properties ofthe polycarbonates. Generally, the amount of the alcohol(s) (B′) is from0 to 39.9 mol %, based on the entire amount of all of the alcohols (B)and (B′) together. The amount is preferably from 0 to 35 mol %,particularly preferably from 0 to 25 mol %, and very particularlypreferably from 0 to 10 mol %.

The reaction of phosgene, diphosgene, or triphosgene with the alcohol oralcohol mixture generally takes place with elimination of hydrogenchloride, and the reaction of the carbonates with the alcohol or alcoholmixture to give the inventive high-functionality highly branchedpolycarbonate takes place with elimination of the monofunctional alcoholor phenol from the carbonate molecule.

The high-functionality highly branched polycarbonates formed by theinventive process have been terminated after the reaction, i.e. withoutfurther modification, using hydroxy groups and/or using carbonategroups. They have good solubility in various solvents, e.g. in water,alcohols, such as methanol, ethanol, butanol, alcohol/water mixtures,acetone, 2-butanone, ethyl acetate, butyl acetate, methoxypropylacetate, methoxyethyl acetate, tetrahydrofuran, dimethylformamide,dimethylacetamide, N-methylpyrrolidone, ethylene carbonate, or propylenecarbonate.

For the purposes of this invention, a high-functionality polycarbonateis a product which, besides the carbonate groups which form the polymerskeleton, further has at least three, preferably at least six, morepreferably at least ten, terminal or pendant functional groups. Thefunctional groups are carbonate groups and/or OH groups. There is inprinciple no upper restriction on the number of the terminal or pendantfunctional groups, but products having a very high number of functionalgroups can have undesired properties, such as high viscosity or poorsolubility. The highly functional polycarbonates of the presentinvention mostly have not more than 500 terminal or pendant functionalgroups, preferably not more than 100 terminal or pendant functionalgroups.

When preparing the highly functional polycarbonates B1), it is necessaryto adjust the ratio of the compounds comprising OH groups to phosgene orcarbonate in such a way that the simplest resultant condensate(hereinafter termed condensate (K)) comprises an average of either onecarbonate group or carbamoyl group and more than one OH group or one OHgroup and more than one carbonate group or carbamoyl group. The simpleststructure of the condensate (K) composed of a carbonate (A) and a di- orpolyalcohol (B) here results in the arrangement XY_(n) or Y_(n)X, whereX is a carbonate group, Y is a hydroxy group, and n is generally anumber from 1 to 6, preferably from 1 to 4, particularly preferably from1 to 3. The reactive group which is the single resultant group here isgenerally termed “focal group” below.

By way of example, if during the preparation of the simplest condensate(K) from a carbonate and a dihydric alcohol the reaction ratio is 1:1,the average result is a molecule of XY type, illustrated by the generalformula 1.

During the preparation of the condensate (K) from a carbonate and atrihydric alcohol with a reaction ratio of 1:1, the average result is amolecule of XY₂ type, illustrated by the general formula 2. A carbonategroup is focal group here.

During the preparation of the condensate (K) from a carbonate and atetrahydric alcohol, likewise with the reaction ratio 1:1, the averageresult is a molecule of XY₃ type, illustrated by the general formula 3.A carbonate group is focal group here.

R in the formulae 1-3 is as defined at the outset, and R¹ is analiphatic or aromatic radical.

The condensates (K) may, by way of example, also be prepared from acarbonate and a trihydric alcohol, as illustrated by the general formula4, the molar reaction ratio being 2:1. Here, the average result is amolecule of X₂Y type, an OH group being focal group here. In formula 4,R and R¹ are as defined in formulae 1-3.

If difunctional compounds, e.g. a dicarbonate or a diol, are also addedto the components, this extends the chains, as illustrated by way ofexample in the general formula 5. The average result is again a moleculeof XY₂ type, a carbonate group being focal group.

In formula 5, R² is an organic, preferably aliphatic radical, and R andR¹ are as defined above.

It is also possible to use two or more condensates (K) for thesynthesis. Firstly, use may be made here of two or more alcohols or twoor more carbonates. Furthermore, the selection of the ratio of thealcohols used and of the carbonates or of the phosgenes may givemixtures of various condensates of different structure. This may beexplained by way of example for the reaction of a carbonate with atrihydric alcohol. If the starting materials are reacted in a ratio of1:1, as shown in (II), the result is an XY₂ molecule. If the startingmaterials are reacted in a ratio of 2:1, as shown in (IV), the result isan X₂Y molecule. If the ratio is between 1:1 and 2:1 the result is amixture of XY₂ and X₂Y molecules.

According to the invention, the simple condensates (K) described by wayof example in the formulae 1-5 preferentially react intermolecularly toform highly functional polycondensates, hereinafter termedpolycondensates (P). The reaction to give the condensate (K) and to givethe polycondensate (P) usually takes place at a temperature of from 0 to250° C., preferably from 60 to 160° C., in bulk or in solution. Use maygenerally be made here of any of the solvents which are inert withrespect to the respective starting materials. Preference is given to useof organic solvents, e.g. decane, dodecane, benzene, toluene,chlorobenzene, xylene, dimethylformamide, dimethylacetamide, or solventnaphtha.

In one preferred embodiment, the condensation reaction is carried out inbulk. The phenol or the monohydric alcohol ROH liberated during thereaction can be removed by distillation from the reaction equilibrium toaccelerate the reaction, if appropriate at reduced pressure.

If removal by distillation is intended, it is generally advisable to usethose carbonates which liberate alcohols ROH with a boiling point below140° C. during the reaction.

Catalysts or catalyst mixtures may also be added to accelerate thereaction. Suitable catalysts are compounds which catalyze esterificationor transesterification reactions, e.g. alkali metal hydroxides, alkalimetal carbonates, alkali metal hydrogencarbonates, preferably of sodium,or potassium, or of cesium, tertiary amines, guanidines, ammoniumcompounds, phosphonium compounds, organoaluminum, organotin, organozinc,organotitanium, organozirconium, or organobismuth compounds, or elsewhat are known as double metal cyamide (DMC) catalysts, e.g. asdescribed in DE 10138216 or DE 10147712.

It is preferable to use potassium hydroxide, potassium carbonate,potassium hydrogencarbonate, diazabicyclooctane (DABCO),diazabicyclononene (DBN), diazabicycloundecene (DBU), imidazoles, suchas imidazole, 1-methylimidazole, or 1,2-dimethylimidazole, titaniumtetrabutoxide, titanium tetraisopropoxide, dibutyltin oxide, dibutyltindilaurate, stannous dioctoate, zirconium acetylacetonate, or mixturesthereof.

The amount of catalyst generally added is from 50 to 10 000 ppm byweight, preferably from 100 to 5000 ppm by weight, based on the amountof the alcohol mixture or alcohol used.

It is also possible to control the intermolecular polycondensationreaction via addition of the suitable catalyst or else via selection ofa suitable temperature. The average molecular weight of the polymer (P)may moreover be adjusted by way of the composition of the startingcomponents and by way of the residence time.

The condensates (K) and the polycondensates (P) prepared at an elevatedtemperature are usually stable at room temperature for a relatively longperiod.

The nature of the condensates (K) permits polycondensates (P) withdifferent structures to result from the condensation reaction, thesehaving branching but no crosslinking. Furthermore, in the ideal case,the polycondensates (P) have either one carbonate group as focal groupand more than two OH groups or else one OH group as focal group and morethan two carbonate groups. The number of the reactive groups here is theresult of the nature of the condensates (K) used and the degree ofpolycondensation.

By way of example, a condensate (K) according to the general formula 2can react via triple intermolecular condensation to give two differentpolycondensates (P), represented in the general formulae 6 and 7.

In formula 6 and 7, R and R¹ are as defined above.

There are various ways of terminating the intermolecularpolycondensation reaction. B_(y) way of example, the temperature may belowered to a range where the reaction stops and the product (K) or thepolycondensate (P) is storage-stable.

It is also possible to deactivate the catalyst, in the case of basiccatalysts, by way of example, via addition of Lewis acids or protonacids.

In another embodiment, as soon as the intermolecular reaction of thecondensate (K) has produced a polycondensate (P) with the desired degreeof polycondensation, a product having groups reactive toward the focalgroup of (P) may be added to the product (P) to terminate the reaction.For example, in the case of a carbonate group as focal group, by way ofexample, a mono-, di-, or polyamine may be added. In the case of ahydroxy group as focal group, by way of example, a mono-, di-, orpolyisocyanate, or a compound comprising epoxy groups, or an acidderivative which reacts with OH groups, can be added to the product (P).

The inventive highly functional polycarbonates are mostly prepared inthe pressure range from 0.1 mbar to 20 bar, preferably at from 1 mbar to5 bar, in reactors or reactor cascades which are operated batchwise,semicontinuously, or continuously.

The abovementioned adjustment of the reaction conditions and, ifappropriate, selection of the suitable solvent permits furtherprocessing of the inventive products after the preparation processwithout further purification.

In another preferred embodiment, the product is stripped, i.e. freedfrom low-molecular-weight, volatile compounds. To this end, once thedesired degree of conversion has been reached, the catalyst mayoptionally be deactivated and the low-molecular-weight volatileconstituents, e.g. monoalcohols, phenols, carbonates, hydrogen chloride,or highly volatile oligomeric or cyclic compounds, can be removed bydistillation, if appropriate with introduction of a gas, preferablynitrogen, carbon dioxide or air, if appropriate at reduced pressure.

In another preferred embodiment, the inventive polycarbonates maycontain other functional groups besides the functional groups present atthis stage by virtue of the reaction. The functionalization may takeplace during the process for increasing molecular weight, or elsesubsequently, i.e. after completion of the actual polycondensation.

If, prior to or during the process for increasing molecular weight,components are added which have other functional groups or functionalelements besides hydroxy or carbonate groups, the result is apolycarbonate polymer with randomly distributed functionalities otherthan the carbonate or hydroxy groups.

Effects of this type can, by way of example, be achieved via addition,during the polycondensation, of compounds which bear other functionalgroups or functional elements, such as mercapto groups, primary,secondary or tertiary amino groups, ether groups, derivatives ofcarboxylic acids, derivatives of sulfonic acids, derivatives ofphosphonic acids, silane groups, siloxane groups, aryl radicals, orlong-chain alkyl radicals, besides hydroxy groups, carbonate groups, orcarbamoyl groups. Examples of compounds which can be used formodification by means of carbamate groups are ethanolamine,propanolamine, isopropanolamine, 2-(butylamino)ethanol,2-(cyclohexylamino)ethanol, 2-amino-1-butanol, 2-(2′-aminoethoxy)ethanolor higher alkoxylation products of ammonia, 4-hydroxypiperidine,1-hydroxyethylpiperazine, diethanolamine, dipropanolamine,diisopropanolamine, tris(hydroxymethyl)aminomethane,tris(hydroxyethyl)aminomethane, ethylenediamine, propylenediamine,hexamethylenediamine or isophoronediamine.

An example of a compound which can be used for modification withmercapto groups is mercaptoethanol. By way of example, tertiary aminogroups can be produced via incorporation of N-methyldiethanolamine,N-methyldipropanolamine or N,N-dimethylethanolamine. By way of example,ether groups may be generated via co-condensation of dihydric or higherpolyhydric polyetherols. Long-chain alkyl radicals can be introduced viareaction with long-chain alkanediols, and reaction with alkyl or aryldiisocyanates generates polycarbonates having alkyl, aryl, and urethanegroups or having urea groups.

Ester groups can be produced via addition of dicarboxylic acids,tricarboxylic acids, or, by way of example, dimethyl terephthalates, ortricarboxylic esters.

Subsequent functionalization can be achieved by using an additional stepof the process (step c)) to react the resultant highly functional highlybranched, or highly functional hyperbranched polycarbonate with asuitable functionalizing reagent which can react with the OH and/orcarbonate groups or carbamoyl groups of the polycarbonate.

By way of example, highly functional highly branched, or highlyfunctional hyperbranched polycarbonates comprising hydroxy groups can bemodified via addition of molecules comprising acid groups or comprisingisocyanate groups. By way of example, polycarbonates comprising acidgroups can be obtained via reaction with compounds containing anhydridegroups.

Highly functional polycarbonates comprising hydroxy groups may moreoveralso be converted into highly functional polycarbonate polyether polyolsvia reaction with alkylene oxides, e.g. ethylene oxide, propylene oxide,or butylene oxide.

A great advantage of the process is its cost-effectiveness. Both thereaction to give a condensate (K) or polycondensate (P) and also thereaction of (K) or (P) to give polycarbonates with other functionalgroups or elements can take place in one reactor, this beingadvantageous technically and in terms of cost-effectiveness.

The inventive molding compositions comprise, as component B2), at leastone hyperbranched polyester of A_(x)B_(y) type, where

x is at least 1.1, preferably at least 1.3, in particular at least 2

y is at least 2.1, preferably at least 2.5, in particular at least 3.

Use may also be made of mixtures as units A and/or B, of course.

An A_(x)B_(y)-type polyester is a condensate composed of an x-functionalmolecule A and a y-functional molecule B. By way of example, mention maybe made of a polyester composed of adipic acid as molecule A (x=2) andglycerol as molecule B (y=3).

For the purposes of this invention, hyperbranched polyesters B2) arenon-crosslinked macromolecules having hydroxy groups and carbonategroups, these having both structural and molecular non-uniformity. Theirstructure may firstly be based on a central molecule in the same way asdendrimers, but with non-uniform chain length of the branches. Secondly,they may also have a linear structure with functional pendant groups, orelse they may combine the two extremes, having linear and branchedmolecular portions. See also P. J. Flory, J. Am. Chem. Soc. 1952, 74,2718, and H. Frey et al., Chem. Eur. J. 2000, 6, no. 14, 2499 for thedefinition of dendrimeric and hyperbranched polymers.

“Hyperbranched” in the context of the present invention means that thedegree of branching (DB), i.e. the average number of dendritic linkagesplus the average number of end groups per molecule, is from 10 to 99.9%,preferably from 20 to 99%, particularly preferably from 20 to 95%.

“Dendrimeric” in the context of the present invention means that thedegree of branching is from 99.9 to 100%. See H. Frey et al., ActaPolym. 1997, 48, 30 for the definition of “degree of branching”.

Component B2) preferably has an M_(n) of from 300 to 30 000 g/mol, inparticular from 400 to 25 000 g/mol, and very particularly from 500 to20 000 g/mol, determined by means of GPC, PMMA standard,dimethylacetamide eluent.

B2) preferably has an OH number of from 0 to 600 mg KOH/g of polyester,preferably of from 1 to 500 mg KOH/g of polyester, in particular from 20to 500 mg KOH/g of polyester to DIN 53240, and preferably a COOH numberof from 0 to 600 mg KOH/g of polyester, preferably from 1 to 500 mgKOH/g of polyester, and in particular from 2 to 500 mg KOH/g ofpolyester.

The T_(g) is preferably from −50° C. to 140° C., and in particular from−50 to 100° C. (by means of DSC, to DIN 53765).

Preference is particularly given to those components B2) in which atleast one OH or COOH number is greater than 0, preferably greater than0.1, and in particular greater than 0.5.

The inventive component B2) is in particular obtainable via theprocesses described below, inter alia by reacting

-   (a) one or more dicarboxylic acids or one or more derivatives of the    same with one or more at least trihydric alcohols-   or-   (b) one or more tricarboxylic acids or higher polycarboxylic acids    or one or more derivatives of the same with one or more diols    in the presence of a solvent and optionally in the presence of an    inorganic, organometallic, or low-molecular-weight organic catalyst,    or of an enzyme. The reaction in solvent is the preferred    preparation method.

For the purposes of the present invention, highly functionalhyperbranched polyesters B2) have molecular and structuralnon-uniformity. Their molecular non-uniformity distinguishes them fromdendrimers, and they can therefore be prepared at considerably lowercost.

Among the dicarboxylic acids which can be reacted according to variant(a) are, by way of example, oxalic acid, malonic acid, succinic acid,glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid,sebacic acid, undecane-α,ω-dicarboxylic acid, dodecane-α,ω-dicarboxylicacid, cis- and trans-cyclohexane-1,2-dicarboxylic acid, cis- andtrans-cyclohexane-1,3-dicarboxylic acid, cis- andtrans-cyclohexane-1,4-dicarboxylic acid, cis- andtrans-cyclopentane-1,2-dicarboxylic acid, and cis- andtrans-cyclopentane-1,3-dicarboxylic acid,

and the abovementioned dicarboxylic acids may have substitution by oneor more radicals selected from

C₁-C₁₀-alkyl groups, such as methyl, ethyl, n-propyl, isopropyl,n-butyl, isobutyl, sec-butyl, tert-butyl, n-pentyl, isopentyl,sec-pentyl, neopentyl, 1,2-dimethylpropyl, isoamyl, n-hexyl, isohexyl,sec-hexyl, n-heptyl, isoheptyl, n-octyl, 2-ethylhexyl, n-nonyl, andn-decyl,

C₃-C₁₂-cycloalkyl groups, such as cyclopropyl, cyclobutyl, cyclopentyl,cyclohexyl, cycloheptyl, cyclooctyl, cyclononyl, cyclodecyl,cycloundecyl, and cyclododecyl; preference is given to cyclopentyl,cyclohexyl, and cycloheptyl;

alkylene groups, such as methylene or ethylidene, or

C₆-C₁₄-aryl groups, such as phenyl, 1-naphthyl, 2-naphthyl, 1-anthryl,2-anthryl, 9-anthryl, 1-phenanthryl, 2-phenanthryl, 3-phenanthryl,4-phenanthryl, and 9-phenanthryl, preferably phenyl, 1-naphthyl, and2-naphthyl, particularly preferably phenyl.

Examples which may be mentioned of representatives of substituteddicarboxylic acids are: 2-methylmalonic acid, 2-ethylmalonic acid,2-phenylmalonic acid, 2-methylsuccinic acid, 2-ethylsuccinic acid,2-phenylsuccinic acid, itaconic acid, 3,3-dimethylglutaric acid.

Among the dicarboxylic acids which can be reacted according to variant(a) are also ethylenically unsaturated acids, such as maleic acid andfumaric acid, and aromatic dicarboxylic acids, such as phthalic acid,isophthalic acid or terephthalic acid.

It is also possible to use mixtures of two or more of the abovementionedrepresentative compounds.

The dicarboxylic acids may either be used as they stand or be used inthe form of derivatives.

Derivatives are preferably

-   -   the relevant anhydrides in monomeric or else polymeric form,    -   mono- or dialkyl esters, preferably mono- or dimethyl esters, or        the corresponding mono- or diethyl esters, or else the mono- and        dialkyl esters derived from higher alcohols, such as n-propanol,        isopropanol, n-butanol, isobutanol, tert-butanol, n-pentanol,        n-hexanol,    -   and also mono- and divinyl esters, and    -   mixed esters, preferably methyl ethyl esters.

In the preferred preparation process it is also possible to use amixture composed of a dicarboxylic acid and one or more of itsderivatives. Equally, it is possible to use a mixture of two or moredifferent derivatives of one or more dicarboxylic acids.

It is particularly preferable to use succinic acid, glutaric acid,adipic acid, phthalic acid, isophthalic acid, terephthalic acid, or themono- or dimethyl ester thereof. It is very particularly preferable touse adipic acid.

Examples of at least trihydric alcohols which may be reacted are:glycerol, butane-1,2,4-triol, n-pentane-1,2,5-triol,n-pentane-1,3,5-triol, n-hexane-1,2,6-triol, n-hexane-1,2,5-triol,n-hexane-1,3,6-triol, trimethylolbutane, trimethylolpropane orditrimethylolpropane, trimethylolethane, pentaerythritol ordipentaerythritol; sugar alcohols, such as mesoerythritol, threitol,sorbitol, mannitol, or mixtures of the above at least trihydricalcohols. It is preferable to use glycerol, trimethylolpropane,trimethylolethane, and pentaerythritol.

Examples of tricarboxylic acids or polycarboxylic acids which can bereacted according to variant (b) are benzene-1,2,4-tricarboxylic acid,benzene-1,3,5-tricarboxylic acid, benzene-1,2,4,5-tetracarboxylic acid,and mellitic acid.

Tricarboxylic acids or polycarboxylic acids can be used in the inventivereaction either as they stand or else in the form of derivatives.

Derivatives are preferably

-   -   the relevant anhydrides in monomeric or else polymeric form,    -   mono-, di-, or trialkyl esters, preferably mono-, di-, or        trimethyl esters, or the corresponding mono-, di-, or triethyl        esters, or else the mono-, di-, and triesters derived from        higher alcohols, such as n-propanol, isopropanol, n-butanol,        isobutanol, tert-butanol, n-pentanol, n-hexanol, or else mono-,        di-, or trivinyl esters    -   and mixed methyl ethyl esters.

For the purposes of the present invention, it is also possible to use amixture composed of a tri- or polycarboxylic acid and one or more of itsderivatives. For the purposes of the present invention it is likewisepossible to use a mixture of two or more different derivatives of one ormore tri- or polycarboxylic acids, in order to obtain component B2).

Examples of diols used for variant (b) of the present invention areethylene glycol, propane-1,2-diol, propane-1,3-diol, butane-1,2-diol,butane-1,3-diol, butane-1,4-diol, butane-2,3-diol, pentane-1,2-diol,pentane-1,3-diol, pentane-1,4-diol, pentane-1,5-diol, pentane-2,3-diol,pentane-2,4-diol, hexane-1,2-diol, hexane-1,3-diol, hexane-1,4-diol,hexane-1,5-diol, hexane-1,6-diol, hexane-2,5-diol, heptan-1,2-diol,1,7-heptanediol, 1,8-octanediol, 1,2-octanediol, 1,9-nonanediol,1,10-decanediol, 1,2-decanediol, 1,12-dodecanediol, 1,2-dodecanediol,1,5-hexadiene-3,4-diol, cyclopentanediols, cyclohexanediols, inositoland derivatives, (2)-methylpentane-2,4-diol,2,4-dimethylpentane-2,4-diol, 2-ethylhexane-1,3-diol,2,5-dimethylhexane-2,5-diol, 2,2,4-trimethylpentane-1,3-diol, pinacol,diethylene glycol, triethylene glycol, dipropylene glycol, tripropyleneglycol, polyethylene glycols HO(CH₂CH₂O)_(n)—H or polypropylene glycolsHO(CH[CH₃]CH₂O)_(n)—H or mixtures of two or more representativecompounds of the above compounds, where n is a whole number and n=from 4to 25. One, or else both, hydroxy groups here in the abovementioneddiols may also be substituted by SH groups. Preference is given toethylene glycol, propane-1,2-diol, and diethylene glycol, triethyleneglycol, dipropylene glycol, and tripropylene glycol.

The molar ratio of the molecules A to molecules B in the A_(x)B_(y)polyester in the variants (a) and (b) is from 4:1 to 1:4, in particularfrom 2:1 to 1:2.

The at least trihydric alcohols reacted according to variant (a) of theprocess may have hydroxy groups of which all have identical reactivity.Preference is also given here to at least trihydric alcohols whose OHgroups initially have identical reactivity, but where reaction with atleast one acid group can induce a fall-off in reactivity of theremaining OH groups as a result of steric or electronic effects. By wayof example, this applies when trimethylolpropane or pentaerythritol isused.

However, the at least trihydric alcohols reacted according to variant(a) may also have hydroxy groups having at least two different chemicalreactivities.

The different reactivity of the functional groups here may either derivefrom chemical causes (e.g. primary/secondary/tertiary OH group) or fromsteric causes.

By way of example, the triol may comprise a triol which has primary andsecondary hydroxy groups, preferred example being glycerol.

When the inventive reaction is carried out according to variant (a), itis preferable to operate in the absence of diols and monohydricalcohols.

When the inventive reaction is carried out according to variant (b), itis preferable to operate in the absence of mono- or dicarboxylic acids.

The inventive process is carried out in the presence of a solvent.Examples of suitable compounds are hydrocarbons, such as paraffins oraromatics. Particularly suitable paraffins are n-heptane andcyclohexane. Particularly suitable aromatics are toluene, ortho-xylene,meta-xylene, para-xylene, xylene in the form of an isomer mixture,ethylbenzene, chlorobenzene and ortho- and meta-dichlorobenzene. Othervery particularly suitable solvents in the absence of acidic catalystsare: ethers, such as dioxane or tetrahydrofuran, and ketones, such asmethyl ethyl ketone and methyl isobutyl ketone.

According to the invention, the amount of solvent added is at least 0.1%by weight, based on the weight of the starting materials used and to bereacted, preferably at least 1% by weight, and particularly preferablyat least 10% by weight. It is also possible to use excesses of solvent,based on the weight of starting materials used and to be reacted, e.g.from 1.01 to 10 times the amount. Solvent amounts of more than 100 timesthe weight of the starting materials used and to be reacted are notadvantageous, because the reaction rate reduces markedly at markedlylower concentrations of the reactants, giving uneconomically longreaction times.

To carry out the process preferred according to the invention,operations may be carried out in the presence of a dehydrating agent asadditive, added at the start of the reaction. Suitable examples aremolecular sieves, in particular 4 Å molecular sieve, MgSO₄, and Na₂SO₄.During the reaction it is also possible to add further dehydrating agentor to replace dehydrating agent by fresh dehydrating agent. During thereaction it is also possible to remove the water or alcohol formed bydistillation and, for example, to use a water separator.

The reaction may be carried out in the absence of acidic catalysts. Itis preferable to operate in the presence of an acidic inorganic,organometallic, or organic catalyst, or a mixture composed of two ormore acidic inorganic, organometallic, or organic catalysts.

For the purposes of the present invention, examples of acidic inorganiccatalysts are sulfuric acid, phosphoric acid, phosphonic acid,hypophosphorous acid, aluminum sulfate hydrate, alum, acidic silica gel(pH=6, in particular =5), and acidic aluminum oxide. Examples of othercompounds which can be used as acidic inorganic catalysts are aluminumcompounds of the general formula Al(OR)₃ and titanates of the generalformula Ti(OR)₄, where each of the radicals R may be identical ordifferent and is selected independently of the others from

C₁-C₁₀-alkyl radicals, such as methyl, ethyl, n-propyl, isopropyl,n-butyl, isobutyl, sec-butyl, tert-butyl, n-pentyl, isopentyl,sec-pentyl, neopentyl, 1,2-dimethylpropyl, isoamyl, n-hexyl, isohexyl,sec-hexyl, n-heptyl, isoheptyl, n-octyl, 2-ethylhexyl, n-nonyl, andn-decyl,

C₃-C₁₂-cycloalkyl radicals, such as cyclopropyl, cyclobutyl,cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, cyclononyl,cyclodecyl, cycloundecyl, and cyclododecyl; preference is given tocyclopentyl, cyclohexyl, and cycloheptyl.

Each of the radicals R in Al(OR)₃ or Ti(OR)₄ is preferably identical andselected from isopropyl or 2-ethylhexyl.

Examples of preferred acidic organometallic catalysts are selected fromdialkyltin oxides R₂SnO, where R is defined as above. A particularlypreferred representative compound for acidic organometallic catalysts isdi-n-butyltin oxide, which is commercially available as “oxo-tin”, ordi-n-butyltin dilaurate.

Preferred acidic organic catalysts are organic compounds having, by wayof example, phosphate groups, sulfonic acid groups, sulfate groups, orphosphonic acid groups. Particular preference is given to sulfonicacids, such as para-toluenesulfonic acid. Acidic ion exchangers may alsobe used as acidic organic catalysts, e.g. polystyrene resins containingsulfonic acid groups and crosslinked with about 2 mol % ofdivinylbenzene.

It is also possible to use combinations of two or more of theabovementioned catalysts. It is also possible to use an immobilized formof those organic or organometallic, or else inorganic catalysts whichtake the form of discrete molecules.

If the intention is to use acidic inorganic, organometallic, or organiccatalysts, according to the invention the amount used is from 0.1 to 10%by weight, preferably from 0.2 to 2% by weight, of catalyst.

The inventive process is carried out under inert gas, e.g. under carbondioxide, nitrogen, or a noble gas, among which mention may particularlybe made of argon.

The inventive process is carried out at temperatures of from 60 to 200°C. It is preferable to operate at temperatures of from 130 to 180° C.,in particular up to 150° C., or below that temperature. Maximumtemperatures up to 145° C. are particularly preferred, and temperaturesup to 135° C. are very particularly preferred.

The pressure conditions for the inventive process are not critical perse. It is possible to operate at markedly reduced pressure, e.g. at from10 to 500 mbar. The inventive process may also be carried out atpressures above 500 mbar. A reaction at atmospheric pressure ispreferred for reasons of simplicity; however, conduct at slightlyincreased pressure is also possible, e.g. up to 1200 mbar. It is alsopossible to operate at markedly increased pressure, e.g. at pressures upto 10 bar. Reaction at atmospheric pressure is preferred.

The reaction time for the inventive process is usually from 10 minutesto 25 hours, preferably from 30 minutes to 10 hours, and particularlypreferably from one to 8 hours.

Once the reaction has ended, the highly functional hyperbranchedpolyesters can easily be isolated, e.g. by removing the catalyst byfiltration and concentrating the mixture, the concentration process hereusually being carried out at reduced pressure. Other work-up methodswith good suitability are precipitation after addition of water,followed by washing and drying.

Component B2) can also be prepared in the presence of enzymes ordecomposition products of enzymes (according to DE-A 101 63163). For thepurposes of the present invention, the term acidic organic catalystsdoes not include the dicarboxylic acids reacted according to theinvention.

It is preferable to use lipases or esterases. Lipases and esterases withgood suitability are Candida cylindracea, Candida lipolytica, Candidarugosa, Candida antarctica, Candida utilis, Chromobacterium viscosum,Geolrichum viscosum, Geotrichum candidum, Mucor javanicus, Mucor mihei,pig pancreas, pseudomonas spp., pseudomonas fluorescens, Pseudomonascepacia, Rhizopus arrhizus, Rhizopus delemar, Rhizopus niveus, Rhizopusoryzae, Aspergillus niger, Penicillium roquefortii, Penicilliumcamembertii, or esterase from Bacillus spp. and Bacillusthermoglucosidasius. Candida antarctica lipase B is particularlypreferred. The enzymes listed are commercially available, for examplefrom Novozymes Biotech Inc., Denmark.

The enzyme is preferably used in immobilized form, for example on silicagel or Lewatit®. Processes for immobilizing enzymes are known per se,e.g. from Kurt Faber, “Biotransformations in organic chemistry”, 3rdedition 1997, Springer Verlag, Chapter 3.2 “Immobilization” pp. 345-356.Immobilized enzymes are commercially available, for example fromNovozymes Biotech Inc., Denmark.

The amount of immobilized enzyme used is from 0.1 to 20% by weight, inparticular from 10 to 15% by weight, based on the total weight of thestarting materials used and to be reacted.

The inventive process is carried out at temperatures above 60° C. It ispreferable to operate at temperatures of 100° C. or below thattemperature. Preference is given to temperatures up to 80° C., veryparticular preference is given to temperatures of from 62 to 75° C., andstill more preference is given to temperatures of from 65 to 75° C.

The inventive process is carried out in the presence of a solvent.Examples of suitable compounds are hydrocarbons, such as paraffins oraromatics. Particularly suitable paraffins are n-heptane andcyclohexane. Particularly suitable aromatics are toluene, ortho-xylene,meta-xylene, para-xylene, xylene in the form of an isomer mixture,ethylbenzene, chlorobenzene and ortho- and meta-dichlorobenzene. Othervery particularly suitable solvents are: ethers, such as dioxane ortetrahydrofuran, and ketones, such as methyl ethyl ketone and methylisobutyl ketone.

The amount of solvent added is at least 5 parts by weight, based on theweight of the starting materials used and to be reacted, preferably atleast 50 parts by weight, and particularly preferably at least 100 partsby weight. Amounts of more than 10 000 parts by weight of solvent areundesirable, because the reaction rate decreases markedly at markedlylower concentrations, giving uneconomically long reaction times.

The inventive process is carried out at pressures above 500 mbar.Preference is given to the reaction at atmospheric pressure or slightlyincreased pressure, for example at up to 1200 mbar. It is also possibleto operate under markedly increased pressure, for example at pressuresup to 10 bar. The reaction at atmospheric pressure is preferred.

The reaction time for the inventive process is usually from 4 hours to 6days, preferably from 5 hours to 5 days, and particularly preferablyfrom 8 hours to 4 days.

Once the reaction has ended, the highly functional hyperbranchedpolyesters can easily be isolated, e.g. by removing the catalyst byfiltration and concentrating the mixture, the concentration process hereusually being carried out at reduced pressure. Other work-up methodswith good suitability are precipitation after addition of water,followed by washing and drying.

The highly functional hyperbranched polyesters obtainable by theinventive process feature particularly low content of discolored andresinified material. For the definition of hyperbranched polymers, seealso: P. J. Flory, J. Am. Chem. Soc. 1952, 74, 2718, and A. Sunder etal., Chem. Eur. J. 2000, 6, no. 1, 1-8. However, in the context of thepresent invention, “highly functional hyperbranched” means that thedegree of branching, i.e. the average number of dendritic linkages plusthe average number of end groups per molecule is from 10 to 99.9%,preferably from 20 to 99%, particularly preferably from 30 to 90% (seein this connection H. Frey et al. Acta Polym. 1997, 48, 30).

The inventive polyesters have a molar mass M_(w) of from 500 to 50 000g/mol, preferably from 1000 to 20 000 g/mol, particularly preferablyfrom 1000 to 19 000 g/mol. The polydispersity is from 1.2 to 50,preferably from 1.4 to 40, particularly preferably from 1.5 to 30, andvery particularly preferably from 1.5 to 10. They are usually verysoluble, i.e. clear solutions can be prepared using up to 50% by weight,in some cases even up to 80% by weight, of the inventive polyesters intetrahydrofuran (THF), n-butyl acetate, ethanol, and numerous othersolvents, with no gel particles detectable by the naked eye.

The inventive highly functional hyperbranched polyesters arecarboxy-terminated, carboxy- and hydroxy-terminated, and preferablyhydroxy-terminated.

The ratios of the components B1): B2) are preferably from 1:20 to 20:1,in particular from 1:15 to 15:1, and very particularly from 1:5 to 5:1.

The hyperbranched polycarbonates B1)/polyesters B2) used take the formof particles of size from 20 to 500 nm. These nanoparticles are presentin fine dispersion in the polymer blend, and the size of the particlesin the compounded material is from 20 to 500 nm, preferably from 50 to300 nm.

Compounded materials of this type are commercially available asUltradur® high speed.

The inventive molding compositions comprise, as component C), from 1 to30% by weight, preferably from 2 to 25% by weight, and in particularfrom 5 to 20% by weight, of a flame retardant combination composed of

-   C1) from 20 to 99% by weight, preferably from 50 to 85% by weight,    of a halogen-containing flame retardant,-   C2) from 1 to 80% by weight, preferably from 15 to 50% by weight, of    an antimony oxide.

Preferred oxides C2) are antimony trioxide and antimony pentoxide. Forbetter dispersion, the oxide C2) may be incorporated in what are knownas masterbatches (concentrates) into the polymer A), and polymers usedin this concentrate may, by way of example, be the same as component A)or different from the respective component A). Preference is given toconcentrates of C2) in polyolefins, preferably polyethylene.

Suitable flame retardants C1) are preferably brominated compounds, suchas brominated diphenyl ethers, brominated trimethylphenylindanes (FR1808 from DSB), tetrabromobisphenol A, and hexabromocyclododecane.

Suitable flame retardants C1) are preferably brominated compounds, suchas brominated oligocarbonates (BC 52 or BC 58 from Great Lakes) of thestructural formula:

Polypentabromobenzyl acrylates, where n>4, e.g. FR 1025 from Dead SeaBromine (DSB) of the formula:

are also suitable.

Other preferred brominated compounds are oligomeric reaction products(n>3) derived from tetrabromobisphenol A with epoxides (e.g. FR 2300 and2400 from DSB) of the formula:

The brominated oligostyrenes preferably used as flame retardant have anaverage degree of polymerization (number-average) of from 3 to 90,preferably from 5 to 60, measured by vapor pressure osmometry intoluene. Cyclic oligomers are likewise suitable. In one preferredembodiment of the invention, the brominated oligomeric styrenes to beused have the following formula 1, where R is hydrogen or an aliphaticradical, in particular an alkyl radical, such as CH₂ or C₂H₅, and n isthe number of repeat units in the chain. R′ can be either H or elsebromine or else a fragment of a customary free-radical generator:

The value n can be from 1 to 88, preferably from 3 to 58. The brominatedoligostyrenes comprise from 40 to 80% by weight of bromine, preferablyfrom 55 to 70% by weight. Preference is given to a product which iscomposed mainly of polydibromostyrene. The substances can be meltedwithout decomposition and, by way of example, aretetrahydrofuran-soluble. They may be prepared either via ringbromination of—if appropriate aliphatically hydrogenated—styreneoligomers, such as those obtainable via thermal polymerization ofstyrene (to DT-A 25 37 385) or via free-radical oligomerization ofsuitable brominated styrenes. The flame retardant may also be preparedvia ionic oligomerization of styrene followed by bromination. The amountof brominated oligostyrene needed to render the polyamides flameretardant depends on the bromine content. The bromine content in theinventive molding compositions is from 2 to 20% by weight, preferablyfrom 5 to 12% by weight.

The brominated polystyrenes of the invention are usually obtained by theprocess described in EP-A 47 549:

The brominated polystyrenes obtainable by this process and availablecommercially are mainly ring-substituted tribrominated products. n′ (seeIII) generally has values of from 125 to 1500, corresponding to amolecular weight of from 42 500 to 235 000, preferably from 130 000 to135 000.

The bromine content (based on the content of ring-substituted bromine)is generally at least 50% by weight, preferably at least 60% by weight,and in particular 65% by weight.

The pulverulent products obtainable commercially generally have a glasstransition temperature of from 160 to 200° C. and are available, by wayof example, with the names HP 7010 from Albemarle and Pyrocheck PB 68from Ferro Corporation.

It is also possible to use mixtures of the brominated oligostyrenes withbrominated polystyrenes in the inventive molding compositions, in anydesired mixing ratio.

Chlorine-containing flame retardants C1) are also suitable, andDeclorane plus from Oxychem is preferred.

The inventive molding compositions may comprise, as component D), from 0to 60% by weight, in particular up to 50% by weight, of other additivesand processing aids.

The inventive molding composition may comprise, as component D), from 0to 5% by weight, preferably from 0.05 to 3% by weight, and in particularfrom 0.1 to 2% by weight, of at least one ester or amide of saturated orunsaturated aliphatic carboxylic acids having from 10 to 40 carbonatoms, preferably from 16 to 22 carbon atoms, with aliphatic saturatedalcohols or amines having from 2 to 40 carbon atoms, preferably from 2to 6 carbon atoms.

The carboxylic acids may be monobasic or dibasic. Examples which may bementioned are pelargonic acid, palmitic acid, lauric acid, margaricacid, dodecanedioic acid, behenic acid, and particularly preferablystearic acid, capric acid, and also montanic acid (a mixture of fattyacids having from 30 to 40 carbon atoms).

The aliphatic alcohols may be mono- to tetrahydric. Examples of alcoholsare n-butanol, n-octanol, stearyl alcohol, ethylene glycol, propyleneglycol, neopentyl glycol, pentaerythritol, preference being given toglycerol and pentaerythritol.

The aliphatic amines may be mono-, di- or triamines. Examples of theseare stearylamine, ethylenediamine, propylenediamine,hexamethylenediamine, di(6-aminohexyl)amine, particular preference beinggiven to ethylenediamine and hexamethylenediamine. Correspondingly,preferred esters or amides are glycerol distearate, glyceroltristearate, ethylenediamine distearate, glycerol monopalmitate,glyceryl trilaurate, glyceryl monobehenate, and pentaerythrityltetrastearate.

It is also possible to use mixtures of various esters or amides, oresters with amides combined, the mixing ratio here being as desired.

Examples of amounts of other usual additives D) are up to 40% by weight,preferably up to 30% by weight, of elastomeric polymers (also oftentermed impact modifiers, elastomers, or rubbers).

These are very generally copolymers which have preferably been built upfrom at least two of the following monomers: ethylene, propylene,butadiene, isobutene, isoprene, chloroprene, vinyl acetate, styrene,acrylonitrile and acrylates and/or methacrylates having from 1 to 18carbon atoms in the alcohol component.

Polymers of this type are described, for example, in Houben-Weyl,Methoden der organischen Chemie, Vol. 14/1 (Georg-Thieme-Verlag,Stuttgart, Germany, 1961), pages 392-406, and in the monograph by C. B.Bucknall, “Toughened Plastics” (Applied Science Publishers, London, UK,1977).

Some preferred types of such elastomers are described below.

Preferred types of such elastomers are those known as ethylene-propylene(EPM) and ethylene-propylene-diene (EPDM) rubbers.

EPM rubbers generally have practically no residual double bonds, whereasEPDM rubbers may have from 1 to 20 double bonds per 100 carbon atoms.

Examples which may be mentioned of diene monomers for EPDM rubbers areconjugated dienes, such as isoprene and butadiene, non-conjugated dieneshaving from 5 to 25 carbon atoms, such as 1,4-pentadiene, 1,4-hexadiene,1,5-hexadiene, 2,5-dimethyl-1,5-hexadiene and 1,4-octadiene, cyclicdienes, such as cyclopentadiene, cyclohexadienes, cyclooctadienes anddicyclopentadiene, and also alkenylnorbornenes, such as5-ethylidene-2-norbornene, 5-butylidene-2-norbornene,2-methallyl-5-norbornene and 2-isopropenyl-5-norbornene, andtricyclodienes, such as 3-methyltricyclo[5.2.1.0^(2,6)]-3,8-decadiene,and mixtures of these. Preference is given to 1,5-hexadiene,5-ethylidenenorbornene and dicyclopentadiene. The diene content of theEPDM rubbers is preferably from 0.5 to 50% by weight, in particular from1 to 8% by weight, based on the total weight of the rubber.

EPM and EPDM rubbers may preferably also have been grafted with reactivecarboxylic acids or with derivatives of these. Examples of these areacrylic acid, methacrylic acid and derivatives thereof, e.g.glycidyl(meth)acrylate, and also maleic anhydride.

Copolymers of ethylene with acrylic acid and/or methacrylic acid and/orwith the esters of these acids are another group of preferred rubbers.The rubbers may also comprise dicarboxylic acids, such as maleic acidand fumaric acid, or derivatives of these acids, e.g. esters andanhydrides, and/or monomers comprising epoxy groups. These monomerscomprising dicarboxylic acid derivatives or comprising epoxy groups arepreferably incorporated into the rubber by adding to the monomer mixturemonomers comprising dicarboxylic acid groups and/or epoxy groups andhaving the general formula I, II, III or IVR¹C(COOR²)═C(COOR³)R⁴  (I)

where R¹ to R⁹ are hydrogen or alkyl having from 1 to 6 carbon atoms,and m is a whole number from 0 to 20, g is a whole number from 0 to 10and p is a whole number from 0 to 5.

R¹ to R⁹ are preferably hydrogen, where m is 0 or 1 and g is 1. Thecorresponding compounds are maleic acid, fumaric acid, maleic anhydride,allyl glycidyl ether and vinyl glycidyl ether.

Preferred compounds of the formulae 1, II and IV are maleic acid, maleicanhydride and (meth)acrylates containing epoxy groups, such as glycidylacrylate and glycidyl methacrylate, and the esters with tertiaryalcohols, such as tert-butyl acrylate. Although the latter have no freecarboxy groups, their behavior approximates to that of the free acidsand they are therefore termed monomers with latent carboxy groups.

The copolymers are advantageously composed of from 50 to 98% by weightof ethylene, from 0.1 to 20% by weight of monomers comprising epoxygroups and/or methacrylic acid and/or monomers comprising anhydridegroups, the remaining amount being (meth)acrylates.

Particular preference is given to copolymers composed of

from 50 to 98% by weight, in particular from 55 to 95% by weight, ofethylene,

from 0.1 to 40% by weight, in particular from 0.3 to 20% by weight, ofglycidyl acrylate and/or glycidyl methacrylate, (meth)acrylic acidand/or maleic anhydride, and

from 1 to 45% by weight, in particular from 10 to 40% by weight, ofn-butyl acrylate and/or 2-ethylhexyl acrylate.

Other preferred (meth)acrylates are the methyl, ethyl, propyl, isobutyland tert-butyl esters.

Besides these, comonomers which may be used are vinyl esters and vinylethers.

The ethylene copolymers described above may be prepared by processesknown per se, preferably by random copolymerization at high pressure andelevated temperature. Appropriate processes are well known.

Other preferred elastomers are emulsion polymers whose preparation isdescribed, for example, by Blackley in the monograph “Emulsionpolymerization”. The emulsifiers and catalysts which can be used areknown per se.

In principle it is possible to use homogeneously structured elastomersor else those with a shell structure. The shell-type structure isdetermined by the sequence of addition of the individual monomers. Themorphology of the polymers is also affected by this sequence ofaddition.

Monomers which may be mentioned here, merely as examples, for thepreparation of the rubber fraction of the elastomers are acrylates, suchas n-butyl acrylate and 2-ethylhexyl acrylate, correspondingmethacrylates, butadiene and isoprene, and also mixtures of these. Thesemonomers may be copolymerized with other monomers, such as styrene,acrylonitrile, vinyl ethers and with other acrylates or methacrylates,such as methyl methacrylate, methyl acrylate, ethyl acrylate or propylacrylate.

The soft or rubber phase (with a glass transition temperature of below0° C.) of the elastomers may be the core, the outer envelope or anintermediate shell (in the case of elastomers whose structure has morethan two shells). Elastomers having more than one shell may also havemore than one shell composed of a rubber phase.

If one or more hard components (with glass transition temperatures above20° C.) are involved, besides the rubber phase, in the structure of theelastomer, these are generally prepared by polymerizing, as principalmonomers, styrene, acrylonitrile, methacrylonitrile, α-methylstyrene,p-methylstyrene, or acrylates or methacrylates, such as methyl acrylate,ethyl acrylate or methyl methacrylate. Besides these, it is alsopossible to use relatively small proportions of other comonomers.

It has proven advantageous in some cases to use emulsion polymers whichhave reactive groups at their surfaces. Examples of groups of this typeare epoxy, carboxy, latent carboxy, amino and amide groups, and alsofunctional groups which may be introduced by concomitant use of monomersof the general formula

where:

-   R¹⁰ is hydrogen or C₁-C₄-alkyl,-   R¹¹ is hydrogen or C₁-C₈-alkyl or aryl, in particular phenyl,-   R¹² is hydrogen, C₁-C₁₀-alkyl, C₆-C₁₂-aryl or —OR¹³-   R¹³ is C₁-C₈-alkyl or C₆-C₁₂-aryl, if appropriate with substitution    by O- or N-containing groups,-   X is a chemical bond or C₁-C₁₀-alkylene or C₆-C₁₂-arylene, or-   Y is O-Z or NH-Z, and-   Z is C₁-C₁₀-alkylene or C₆-C₁₂-arylene.

The graft monomers described in EP-A 208 187 are also suitable forintroducing reactive groups at the surface.

Other examples which may be mentioned are acrylamide, methacrylamide andsubstituted acrylates or methacrylates, such as (N-tert-butylamino)ethylmethacrylate, (N,N-dimethylamino)ethyl acrylate,(N,N-dimethylamino)methyl acrylate and (N,N-diethylamino)ethyl acrylate.

The particles of the rubber phase may also have been crosslinked.Examples of crosslinking monomers are 1,3-butadiene, divinylbenzene,diallyl phthalate and dihydrodicyclopentadienyl acrylate, and also thecompounds described in EP-A 50 265.

It is also possible to use the monomers known as graft-linking monomers,i.e. monomers having two or more polymerizable double bonds which reactat different rates during the polymerization. Preference is given to theuse of compounds of this type in which at least one reactive grouppolymerizes at about the same rate as the other monomers, while theother reactive group (or reactive groups), for example, polymerize(s)significantly more slowly. The different polymerization rates give riseto a certain proportion of unsaturated double bonds in the rubber. Ifanother phase is then grafted onto a rubber of this type, at least someof the double bonds present in the rubber react with the graft monomersto form chemical bonds, i.e. the phase grafted on has at least somedegree of chemical bonding to the graft base.

Examples of graft-linking monomers of this type are monomers comprisingallyl groups, in particular allyl esters of ethylenically unsaturatedcarboxylic acids, for example allyl acrylate, allyl methacrylate,diallyl maleate, diallyl fumarate and diallyl itaconate, and thecorresponding monoallyl compounds of these dicarboxylic acids. Besidesthese there is a wide variety of other suitable graft-linking monomers.For further details reference may be made here, for example, to U.S.Pat. No. 4,148,846.

The proportion of these crosslinking monomers in the impact-modifyingpolymer is generally up to 5% by weight, preferably not more than 3% byweight, based on the impact-modifying polymer.

Some preferred emulsion polymers are listed below. Mention may first bemade here of graft polymers with a core and with at least one outershell, and having the following structure: Type Monomers for the coreMonomers for the envelope I 1,3-butadiene, isoprene, n-butyl acrylate,styrene, acrylonitrile, methyl ethylhexyl acrylate, or a mixture ofmethacrylate these II as I, but with concomitant use of as Icrosslinking agents III as I or II n-butyl acrylate, ethyl acrylate,methyl acrylate, 1,3-butadiene, isoprene, ethylhexyl acrylate IV as I orII as I or III, but with concomitant use of monomers having reactivegroups, as described herein V styrene, acrylonitrile, methylmethacrylate, first envelope composed of monomers or a mixture of theseas described under I and II for the core, second envelope as describedunder I or IV for the envelope

These graft polymers, in particular ABS polymers and/or ASA polymers,are preferably used in amounts of up to 40% by weight for theimpact-modification of PBT, if appropriate in a mixture with up to 40%by weight of polyethylene terephthalate. Blend products of this type areobtainable with the trademark Ultradur®S (previously Ultrablend®S fromBASF AG).

Instead of graft polymers whose structure has more than one shell, it isalso possible to use homogeneous, i.e. single-shell, elastomers composedof 1,3-butadiene, isoprene and n-butyl acrylate or from copolymers ofthese. These products, too, may be prepared by concomitant use ofcrosslinking monomers or of monomers having reactive groups.

Examples of preferred emulsion polymers are n-butylacrylate-(meth)acrylic acid copolymers, n-butyl acrylate-glycidylacrylate or n-butyl acrylate-glycidyl methacrylate copolymers, graftpolymers with an inner core composed of n-butyl acrylate or based onbutadiene and with an outer envelope composed of the abovementionedcopolymers, and copolymers of ethylene with comonomers which supplyreactive groups.

The elastomers described may also be prepared by other conventionalprocesses, e.g. by suspension polymerization.

Preference is also given to silicone rubbers, as described in DE-A 37 25576, EP-A 235 690, DE-A 38 00 603 and EP-A 319 290.

It is, of course, also possible to use mixtures of the types of rubberlisted above.

Fibrous or particulate fillers D) which may be mentioned are carbonfibers, glass fibers, glass beads, amorphous silica, asbestos, calciumsilicate, calcium metasilicate, magnesium carbonate, kaolin, chalk,powdered quartz, mica, barium sulfate and feldspar, used in amounts ofup to 50% by weight, in particular up to 40% by weight.

Preferred fibrous fillers which may be mentioned are carbon fibers,aramid fibers and potassium titanate fibers, and particular preferenceis given to glass fibers in the form of E glass. These may be used asrovings or in the commercially available forms of chopped glass.

Particular preference is given to mixtures of glass fibers D) withcomponent B) in a ratio of from 1:100 to 1:2, preferably from 1:10 to1:3.

The fibrous fillers may have been surface-pretreated with a silanecompound to improve compatibility with the thermoplastic.

Suitable silane compounds have the formula:(X—(CH₂)_(n))_(k)—Si—(O—C_(m)H_(2m+1))_(4-k)where:

n is a whole number from 2 to 10, preferably 3 to 4,m is a whole number from 1 to 5, preferably 1 to 2, andk is a whole number from 1 to 3, preferably 1.

Preferred silane compounds are aminopropyltrimethoxysilane,aminobutyltrimethoxysilane, aminopropyltriethoxysilane andaminobutyltriethoxysilane, and also the corresponding silanes whichcomprise a glycidyl group as substituent X.

The amounts of the silane compounds generally used for surface-coatingare from 0.05 to 5% by weight, preferably from 0.5 to 1.5% by weight andin particular from 0.8 to 1% by weight (based on D).

Acicular mineral fillers are also suitable.

For the purposes of the invention, acicular mineral fillers are mineralfillers with strongly developed acicular character. An example isacicular wollastonite. The mineral preferably has an L/D (length todiameter) ratio of from 8:1 to 35:1, preferably from 8:1 to 11:1. Themineral filler may, if appropriate, have been pretreated with theabovementioned silane compounds, but the pretreatment is not essential.

Other fillers which may be mentioned are kaolin, calcined kaolin,wollastonite, talc and chalk.

As component D), the thermoplastic molding compositions of the inventionmay comprise the usual processing aids, such as stabilizers, oxidationretarders, agents to counteract decomposition due to heat anddecomposition due to ultraviolet light, lubricants and mold-releaseagents, colorants, such as dyes and pigments, nucleating agents,plasticizers, etc.

Examples which may be mentioned of oxidation retarders and heatstabilizers are sterically hindered phenols and/or phosphites,hydroquinones, aromatic secondary amines, such as diphenylamines,various substituted members of these groups, and mixtures of these inconcentrations of up to 1% by weight, based on the weight of thethermoplastic molding compositions.

UV stabilizers which may be mentioned, and are generally used in amountsof up to 2% by weight, based on the molding composition, are varioussubstituted resorcinols, salicylates, benzotriazoles, and benzophenones.

Colorants which may be added are inorganic pigments, such as titaniumdioxide, ultramarine blue, iron oxide, and carbon black, and alsoorganic pigments, such as phthalocyanines, quinacridones and perylenes,and also dyes, such as nigrosine and anthraquinones.

Nucleating agents which may be used are sodium phenylphosphinate,alumina, silica, and preferably talc.

The amounts usually used of other lubricants and mold-release agents areup to 1% by weight. Preference is given to long-chain fatty acids (e.g.stearic acid or behenic acid), salts of these (e.g. Ca stearate of Znstearate), or montan waxes (mixtures composed of straight-chain,saturated carboxylic acids having chain lengths of from 28 to 32 carbonatoms), and also to Ca montanate or Na montanate, and also tolow-molecular-weight polyethylene waxes and low-molecular-weightpolypropylene waxes.

Examples of plasticizers which may be mentioned are dioctyl phthalate,dibenzyl phthalate, butyl benzyl phthalate, hydrocarbon oils andN-(n-butyl)benzenesulfonamide.

The inventive molding compositions may also comprise from 0 to 2% byweight of fluorine-containing ethylene polymers. These are polymers ofethylene with a fluorine content of from 55 to 76% by weight, preferablyfrom 70 to 76% by weight.

Examples of these are polytetrafluoroethylene (PTFE),tetrafluoroethylene-hexafluoropropylene copolymers andtetrafluoroethylene copolymers with relatively small proportions(generally up to 50% by weight) of copolymerizable ethylenicallyunsaturated monomers. These are described, for example, by Schildknechtin “Vinyl and Related Polymers”, Wiley-Verlag, 1952, pages 484-494 andby Wall in “Fluoropolymers” (Wiley Interscience, 1972).

These fluorine-containing ethylene polymers have homogeneousdistribution in the molding compositions and preferably have a particlesize d₅₀ (numeric average) in the range from 0.05 to 10 μm, inparticular from 0.1 to 5 μm. These small particle sizes can particularlypreferably be achieved by the use of aqueous dispersions offluorine-containing ethylene polymers and the incorporation of theseinto a polyester melt.

The inventive thermoplastic molding compositions may be prepared bymethods known per se, by mixing the starting components in conventionalmixing apparatus, such as screw extruders, Brabender mixers or Banburymixers, and then extruding them. The extrudate may be cooled andcomminuted. It is also possible to premix individual components and thento add the remaining starting materials individually and/or likewise ina mixture. The mixing temperatures are generally from 230 to 290° C.

In another preferred method of operation, components B) and C) and, ifappropriate, D) may be mixed with a prepolymer, compounded, andpelletized. The resultant pellets are then solid-phase-condensed,continuously or batchwise, under an inert gas, at a temperature belowthe melting point of component A) until the desired viscosity has beenreached.

The inventive thermoplastic molding compositions feature goodflowability together with good mechanical and flame retardancyproperties.

In particular, the processing of the individual components (withoutclumping or caking) is problem-free and possible in short cycle times,permitting in particular an application as thin-walled components, withvery little mold deposit.

The morphology of selected compounded materials were studied bytransmission electron microscopy. Good dispersion of the particles inthe blend was seen. Particle sizes of from 20 to 500 nm were found. Thetypical exudation of the additives was minimized.

These materials are suitable for the production of fibers, films, andmoldings of any type, in particular for applications as plugs, switches,housing parts, housing covers, headlamp bezels, shower heads, fittings,smoothing irons, rotary switches, stove controls, fryer lids, doorhandles, (rear) mirror housings, (tailgate) screen wipers, sheathing foroptical conductors.

EXAMPLES

Component A:

Polybutylene terephthalate with a viscosity number VN of 130 ml/g andwith a carboxy end group content of 34 meq/kg (Ultradur® B 4520 fromBASF AG) (VN measured in 0.5% strength by weight solution ofphenol/o-dichlorobenzene, 1:1 mixture at 25° C.), comprising 0.65% byweight of pentaerythritol tetrastearate (component C1, based on 100% byweight of A).

Preparation Specification for Polycarbonates B1

General Operating Specification:

As shown in table 1, equimolar amounts of the polyhydric alcohol anddiethyl carbonate were mixed in a three-necked flask equipped withstirrer, reflux condenser, and internal thermometer, and 250 ppm ofcatalyst (based on the amount of alcohol) were added. The mixture wasthen heated with stirring to 100° C., and in the experiment indicatedby * to 140° C., and stirred for 2 h at this temperature. Evaporativecooling caused by the monoalcohol liberated reduced the temperature ofthe reaction mixture here as the reaction proceeded. The refluxcondenser was now replaced by an inclined condenser, ethanol was removedby distillation, and the temperature of the reaction mixture wasincreased slowly to 160° C.

The ethanol removed by distillation was collected in a cooledround-bottomed flask, and weighed, and the conversion was thusdetermined as a percentage based on the full conversion theoreticallypossible (see table 1).

The reaction products were then analyzed by gel permeationchromatography, the eluent being dimethylacetamide and the standardbeing polymethyl methacrylate (PMMA). TABLE 1 Amount of ethanoldistillate, based Molecular on full weight Visc. conversion M_(w) 23° OHnumber Alcohol Catalyst [mol %] M_(n) [mPas] [mg KOH/g] TMP × 1.2 POK₂CO₃ 90 1836 7150 300 1292TMP = trimethylolpropanePO = propylene oxideComponent C/1: brominated oligocarbonate (BC 52 from Great Lakes)Bromine content: 51.3%Component C/2: antimony trioxide (in the form of 90% strengthconcentrate in polyethylene)Component D/1: glass fibers with average thickness of 10 μm(epoxysilanized size)Component D/2: polytetrafluoroethylene (Teflon) in the form of a 2%strength masterbatch in PBT.Preparation of Molding Compositions

Components A) to C) were blended at from 250 to 260° C. in a twin-screwextruder and extruded into a waterbath. After pelletization and drying,test specimens were injection molded and tested.

The pellets were injection molded to give dumbell specimens to ISO527-2, and a tensile test was carried out. Impact strength was alsodetermined to ISO 179-2, as were viscosity (solvent for PBT to DIN53728: phenol/1,2-dichlorobenzene (1:1) ISO 1628), MVR (ISO 1133) andflow behavior, and flame retardancy to UL 94.

The inventive compositions and the results of the tests are found in thetables. TABLE 2 Components [% by weight] 1C 2 3 4 A 44.09 43.59 43.3443.09 B/1 — 0.5 0.75 1 C/1 14 14 14 14 C/2 6.2 6.2 6.2 6.2 D/1 30 30 3030 D/2 5.71 5.71 5.71 5.71 Ash % 30/30 29.9/30 30/30 30.4/30.4 VN ml/g118 99 91 83 MVR 275°/2.16 kp cm³/10′ 9.72 27.24 41.32 64.28 Imp. res.to 179-2/1 eU [kJ/m²] 58.3 53.5 53 45.2 Tensile test: modulus of 1149911667 11755 11953 elasticity [MPa] Max. stress [MPa] 140.83 139.44136.55 131.04 Tensile stress at break [MPa] 140.83 139.44 136.55 131.04Max. strain [%] 2.2 2.1 1.9 1.7 Tensile strain at break [%] 2.2 2.1 1.91.7 UL 94, vertical 1.6 mm 1/16 V-0 V-0 V-0 V-0 3.2 mm ⅛ V-0 V-0 V-0 V-0Spiral test, T7, 2 mm [cm] 19.4 27.3 33.3 40.1

TABLE 3 Components [% by weight] 5C 6 7 8 A 64.09 63.59 63.34 63.09 B/1— 0.5 0.75 1 C/1 14 14 14 14 C/2 6.2 6.2 6.2 6.2 D/2 5.71 5.71 5.71 5.71Ash % 9.77/9.47 10.2/10.1 9.94/10.2 10/10.1 VN ml/g 121.5 108 101 97.55MVR 275°/2.16 kp cm³/10′ 21.08 35.8 60.27 79.98 Imp. res. to 179-2/1 eU[kJ/m²] 40.4 31.7 26 24.4 Tensile test: Modulus of 5226 5310 5348 5446elasticity [MPa] Tensile stress at yield [MPa] 90.31 91.74 — — Max.stress [MPa] 90.31 91.8 90.22 84.79 Tensile stress at break [MPa] 89.1491.7 90.22 84.79 Tensile strain at yield [%] 3.1 3 — — Max. strain [%]3.1 3 2.6 2.1 Tensile strain at break [%] — 2.9 2.6 2.1 Nom break [%]3.3 3.1 — — UL 94, vertical 1.6 mm 1/16 V-0 V-0 V-0 V-0 3.2 mm ⅛ V-0 V-0V-0 V-0 Spiral test T7 2 mm [cm] 26.2 35.6 41.6 47.7

1. A thermoplastic molding composition, comprising: A) from 10 to 98% byweight of at least one thermoplastic polymer; B) from 0.01 to 50% byweight of B1) at least one highly branched or hyperbranchedpolycarbonate with an OH number of from 1 to 600 mg KOH/g ofpolycarbonate, or B2) at least one highly branched or hyperbranchedA_(x)B_(y) polyester, wherein x is at least 1.1 and y is at least 2.1,or a mixture thereof; C) from 1 to 30% by weight of a flame retardantcombination composed of, based on 100% by weight of C), C1) from 20 to99% by weight of a halogen-containing flame retardant, and C2) from 1 to80% by weight of an antimony oxide; and D) from 0 to 60% by weight ofother additives, wherein the total of the percentages by weight ofcomponents A) to D) is 100%.
 2. The thermoplastic molding compositionaccording to claim 1, wherein component B1) has a number-average molarmass M_(n) of from 100 to 15 000 g/mol.
 3. The thermoplastic moldingcomposition according to claim 1, wherein component B1) has a glasstransition temperature Tg of from −80° C. to 140° C.
 4. Thethermoplastic molding composition according to claim 1, whereincomponent B1) has a viscosity (mPas) at 23° C. (DIN 53019) of from 50 to200
 000. 5. The thermoplastic molding composition according to claim 1,wherein in component B2) has a number-average molar mass M_(n) of from300 to 30 000 g/mol.
 6. The thermoplastic molding composition accordingto claim 1, wherein component B2) has a glass transition temperatureT_(g) of from −50 to 140° C.
 7. The thermoplastic molding compositionaccording to claim 1, wherein component B2) has an OH number (DIN 53240)of from 0 to 600 mg KOH/g of polyester.
 8. The thermoplastic moldingcomposition according to claim 1, wherein component B2) has a COOHnumber (DIN 53240) of from 0 to 600 mg KOH/g of polyester.
 9. Thethermoplastic molding composition according to claim 1, whereincomponent B2) has at least one OH number or COOH number greater than 0.10. The thermoplastic molding composition according to claim 1, whereinthe ratio of the components B1):B2) is from 1:20 to 20:1.
 11. Thethermoplastic molding composition according to claim 1, wherein thethermoplastic polymer is selected from the group consisting ofpolyamides, polyesters, vinylaromatic polymers, ASA polymers, ABSpolymers, SAN polymers, and mixtures thereof.
 12. The thermoplasticmolding composition according to claim 1, wherein component A) iscomposed of polybutylene terephthalate which may comprise from 0 to 50%by weight, based on 100% by weight of A), of polyesters other thanpolybutylene terephthalate.
 13. The thermoplastic molding compositionaccording to claim 1, wherein C2) is composed of antimony trioxide or ofantimony pentoxide, or of a mixture of these.
 14. (canceled)
 15. Afiber, a foil, or a molding obtained from the thermoplastic moldingcomposition according to claim
 1. 16. A method of making a fiber, foil,or molding, which comprises: preparing a thermoplastic moldingcomposition according to claim 1; and forming a fiber, foil, or moldingfrom the thermoplastic molding composition.
 17. The thermoplasticmolding composition according to claim 2, wherein component B1) has aglass transition temperature Tg of from −80° C. to 140° C.
 18. Thethermoplastic molding composition according to claim 2, whereincomponent B1) has a viscosity (mPas) at 23° C. of from 50 to 200 000.19. The thermoplastic molding composition according to claim 3, whereincomponent B1) has a viscosity (mPas) at 23° C. of from 50 to 200 000.20. The thermoplastic molding composition according to claim 2, whereincomponent B2) has a number-average molar mass M_(n) of from 300 to 30000 g/mol.
 21. The thermoplastic molding composition according to claim3, wherein component B2) has a number-average molar mass M_(n) of from300 to 30 000 g/mol.